Cesar Millan is at the top of the world now, but two years ago, the Dog Whisperer found himself in a very dark place.

In "Cesar Millan: The Real Story," a documentary airing Nov. 25 on Nat Geo Wild, the animal activist reveals that in 2010, he attempted suicide.

"In June 2010, I received news of my divorce while in London and it made my whole world come down," he writes on
his website, without specifically addressing the overdose that resulted in his hospitalization. "I felt defeated, a big sense of guilt and failure ... I was at the lowest level I had ever been emotionally and psychologically."

He was also in mourning for his beloved dog
Daddy, a pit bull "ambassador" who died several months beforehand after being Millan's constant companion for almost 16 years -- the same length as his marriage.

"It took me two years to finally come back to a good place," says Millan, now 43, noting that 2012 "has been a tremendous period of growth, rebuilding and rehabilitation for me and my pack."